Potassic-mangani-leakeite

Chemical formula: KNa₂(Mg₂Mn³⁺₂Li)Si₈O₂₂(OH)₂

Potassic-mangani-leakeite is a rare silicate from the amphibole group, distinguished by its dark red to brownish-violet color and complex chemical composition.

## Characteristics Potassic-mangani-leakeite is a complex inosilicate belonging to the amphibole group, specifically to the leakeite subgroup. It forms elongated, prismatic crystals, often fibrous or in granular aggregates. Its most characteristic visual feature is an intense, dark red to brownish-violet color. It is a transparent mineral with a vitreous luster. ## Physical Properties This mineral is characterized by a hardness in the range of 6-7 on the Mohs scale, making it relatively scratch-resistant. It has a vitreous luster and is transparent. Its density has not been precisely determined. ## Colors and Varieties The observed colors are dark red and brownish-violet. No named varieties of this mineral have been distinguished. ## History and Name Potassic-mangani-leakeite was first described in 1993. Its name refers to its chemical composition – the dominance of potassium (potassic) and manganese (mangani) – and its relation to other minerals of the leakeite group. The group name honors Frank Leake, a British geologist. ## Uses Due to its extreme rarity, potassic-mangani-leakeite has no industrial applications. It is of scientific and collector's interest only.

Properties

Mohs hardness
6-7
Luster
Vitreous
Streak
n.d.
Density
0
Cleavage
Parallel to [001]
Transparency
Transparent
Crystal system
Monoclinic

Diagnostic features

## Identification Key diagnostic features include its unique dark red to brownish-violet color, prismatic crystal habit, and vitreous luster. Occurrence in a specific geological environment (manganese deposits) is also an important clue. However, final identification requires advanced analytical methods, such as chemical composition analysis. ## Distinguishing from Similar Minerals It can be confused with other rare, reddish amphiboles or pyroxenes occurring in similar parageneses. Distinguishing it from closely related minerals of the leakeite group is impossible without detailed laboratory studies. ## Crystal Forms It most often occurs as elongated, columnar, or acicular crystals. It can also form fibrous aggregates or granular masses.

Geological environment

## Genesis This is a metamorphic mineral, forming in manganese ore deposits subjected to metamorphic processes. Its presence is associated with rocks rich in manganese and alkalis. ## Mineral Associations It coexists with other manganese minerals, such as braunite, hematite, as well as various amphiboles and pyroxenes. At its type locality, it was found in association with sugilite and pectolite. ## Localities The only confirmed and described occurrence of this mineral in the world is its type locality – Wessels Mine in the Kalahari Manganese Fields region, Northern Cape Province, Republic of South Africa.

Rarity

Extremely rare

For collectors

## Quality Criteria The most prized specimens are those with well-formed, transparent crystals of intense, red color. Aesthetic composition with associated minerals, for example, a contrasting combination with white pectolite, is also important. Due to its rarity, every specimen, even in aggregate form, holds significant value for specialized collectors. ## Popular Localities The only source of specimens of this mineral is the Wessels Mine in South Africa. This is a classic and highly valued locality, known for supplying many rare and unique manganese minerals.

Care and storage

## Cleaning It is recommended to clean only with a soft brush to remove dust. The use of water, especially with detergents, is inadvisable due to the risk of reaction with the mineral and potential damage to delicate structures. ## What to Avoid Avoid contact with all chemicals, including acids and strong bases. The mineral should be protected from sudden temperature changes and prolonged exposure to direct sunlight, which can affect its color. ## Storage Specimens should be stored in stable conditions, preferably in a closed display box, to protect them from dust, mechanical damage, and moisture. Due to its rarity, particular caution is advised.

External references

Sources

Read more